Orthogonally Polarized Lasers

Lasers generally emit radiation, which is either simply linearly polarized or unpolarized and stochastically polarized. Contrary to these common lasers, all orthogonally polarized lasers simultaneously emit radiation in two linear polarization states, both exactly orthogonally oriented to each other. Due to this orthogonality, both polarized components in the beam are independent of each other to a high degree and the studies presented in this book make clear that this feature can give a strong advantage in certain laser applications, for instance in high-precision measurements.

Orthogonal Polarization in Lasers: Physical Phenomena and Engineering Applications summarizes the basics and advanced research results of orthogonally polarized lasers, birefringence laser cavities, and their applications. The authors include a number of figures, experimental designs, and measurement curves to enable the reader to not only learn the basic principles and technologies but also to understand many applications in modern engineering and to start their own R&D projects.

The book covers polarization effects, which are of fundamental importance across various disciplines of science and technology.

• Includes a number of figures, experimental designs, and measurement curves to help readers learn the basic principles and start their own R&D projects.

• Discusses many types of relevant lasers (helium/neon lasers, ND:YAG lasers, semiconductor lasers, laser diodes).

• Written by multiply-published authors in the subject area.

• Contains material useful for metrology applications.

This book is intended for use by researchers, postgraduates, and engineers working in laser science, optics, and measurement and testing, while senior undergraduate students working in optical and laser science can use the book for advanced understanding in their field.

Auteur

Shulian Zhang, Tsinghua University, P.R. China.

Wolfgang Holzapfel, Tsinghua University, P.R. China.

Contenu
Foreword xvii
by Zhou Bingkun Foreword xix
by Konrad Herrmann

Preface xxi

Introduction xxv

Part One FUNDAMENTALS OF LASERS AND BEAM POLARIZATIONS

1 Rigorous Introduction to Lasers and Beam Polarizations 3

1.1 The Basic Amplifier/Cavity Configuration 3

1.2 Optical Waves of a Laser 4

1.3 Cavity Closed-Loop and Laser Threshold 8

1.4 Survey of Techniques for Generating and Converting Laser Polarization States 16

References 24

2 Basic Physical Effects Inside Lasers 25

2.1 Interaction between Light and Particles 25

2.2 Line Shape Function and the Line Broadening Mechanism 30

2.3 Gain Coefficient of Light in an Active Medium 38

2.4 Saturation of Gain in the Laser Active Medium 40

2.5 Threshold Condition, Gain for Stationary Operation, and Lasing Bandwidth 44

2.6 Optical Cavities and Laser Modes 46

2.7 Laser Mode Competition 50

2.8 Mode Push/Pull and Locking Effects 54

2.9 Power Tuning Properties of Lasers 55

References 59

3 Specific Laser Technologies Applicable for Orthogonally Polarized Beam Generation 61

3.1 Background 61

3.2 HeNe lasers 62

3.3 Carbon Dioxide (CO2) Laser and Its Polarization State 68

3.4 Optically Pumped Nd:YAG Lasers (1.06 m) 69

3.5 Semiconductor Lasers 72

3.6 Fiber Lasers 76

3.7 Conclusions on Relevant Orthogonally Polarized Laser Technologies 78

References 80

Part Two GENERATION OF ORTHOGONAL LASER POLARIZATIONS

4 Zeeman Dual-Frequency Lasers and Multifrequency Ring Lasers Orthogonally Polarized Lasers in Tradition 83

4.1 Introduction 83

4.2 Zeeman Dual-Frequency Lasers 84

4.3 Multifrequency Ring Laser 88

References 96

5 Matrix Theory of Anisotropic Laser Cavities A Further Approach to Orthogonally Polarized Dual-Frequency Lasers 99

5.1 Background 99

5.2 Polarization-Dependent Properties of Optical Materials 100

5.3 Introduction to the Jones Formalism 101

5.4 Mathematical Description of Polarized Light by the Jones Vectors 102

5.5 Transfer Matrixes of Retarders, Rotators, and Polarizers 103

5.6 Serial Connections of Anisotropic Elements and the Jones Theorem 105

5.7 Connection of Different Retardations within the Same Anisotropic Element 107

5.8 Calculation of Eigenpolarizations and Eigenfrequencies of Passive Anisotropic Cavities 107

5.9 Conclusions 111

References 111

6 Orthogonal Polarization and Frequency Splitting in Birefringent Laser Cavities 113

6.1 Laser Frequency Splitting Due to Intracavity Birefringence 113

6.2 Laser Frequency Splitting Caused by Intracavity Quartz Crystals 117

6.3 Laser Frequency Splitting Caused by Intracavity Electro-optic Crystals 125

6.4 Induced Stress Birefringence and Laser Frequency Splitting 129

6.5 Frequency Splitting in Semiconductor Lasers 133

6.6 Frequency Splitting in Fiber Lasers 136

6.7 Observation and Readout of Frequency Splitting 137

6.8 Final Remark on Methods Used to Obtain Small and Also Larger Frequency Differences 143

References 143

7 Design of Orthogonally Polarized Lasers 145

7.1 Background 145

7.2 Quartz Birefringence HeNe Laser 147

7.3 Stress-Induced Birefringence HeNe Laser 150

7.4 Equidistant Frequency Split Ultrashort HeNe Laser 153

7.5 Zeeman Birefringence Dual-Frequency HeNe Laser 154

7.6 HeNe Laser with Two Intracavity Birefringence Elements 158

7.7 Orthogonally Polarized Lasers with a Superposition Layer Birefringence Film 161

7.8 Laser Diode Pumped Birefringent Nd:YAG Laser with Tunable Frequency Difference 163

7.9 Orthogonally Polarized Lasers with Electrically Controllable Frequency Differences 169

References 170 &lt...